1. Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus for handling a radio link failure in a wireless communication system.
2. Related Art
3rd generation partnership project (3GPP) long term evolution (LTE) is an improved version of a universal mobile telecommunication system (UMTS) and is introduced as the 3GPP release 8. The 3GPP LTE uses orthogonal frequency division multiple access (OFDMA) in a downlink, and uses single carrier-frequency division multiple access (SC-FDMA) in an uplink. The 3GPP LTE employs multiple input multiple output (MIMO) having up to four antennas. In recent years, there is an ongoing discussion on 3GPP LTE-advanced (LTE-A) that is an evolution of the 3GPP LTE.
A user equipment (UE) persistently performs measurement to maintain quality of a radio link with a serving cell from which the UE receives a service. The UE determines whether communication is impossible in a current situation due to deterioration of the quality of the radio link with the serving cell. If it is determined that the quality of the serving cell is so poor that communication is currently impossible, the UE determines the current situation as a radio link failure.
Upon detecting the radio link failure, the UE attempts to recover the radio link failure. If the UE is in a radio resource control (RRC) connected mode and the recovery is delayed, quality of service for a user may not be guaranteed.
Accordingly, there is a need for a technique for handling a radio link failure in a RRC connected mode.